The VirtualBox Packer builder is able to create
VirtualBox virtual machines and export them in
the OVF format, starting from an ISO image.

The builder builds a virtual machine by creating a new virtual machine from
scratch, booting it, installing an OS, provisioning software within the OS, then
shutting it down. The result of the VirtualBox builder is a directory containing
all the files necessary to run the virtual machine portably.

Here is a basic example. This example is not functional. It will start the OS
installer but then fail because we don't provide the preseed file for Ubuntu to
self-install. Still, the example serves to show the basic configuration:

There are many configuration options available for the VirtualBox builder. They
are organized below into two categories: required and optional. Within each
category, the available options are alphabetized and described.

In addition to the options listed here, a
communicator can be configured for this
builder.

iso_checksum (string) - The checksum for the OS ISO file. Because ISO
files are so large, this is required and Packer will verify it prior to
booting a virtual machine with the ISO attached. The type of the checksum is
specified with iso_checksum_type, documented below. At least one of
iso_checksum and iso_checksum_url must be defined. This has precedence
over iso_checksum_url type.

iso_checksum_type (string) - The type of the checksum specified in
iso_checksum. Valid values are none, md5, sha1, sha256, or
sha512 currently. While none will skip checksumming, this is not
recommended since ISO files are generally large and corruption does happen
from time to time.

iso_checksum_url (string) - A URL to a GNU or BSD style checksum file
containing a checksum for the OS ISO file. At least one of iso_checksum
and iso_checksum_url must be defined. This will be ignored if
iso_checksum is non empty.

iso_url (string) - A URL to the ISO containing the installation image.
This URL can be either an HTTP URL or a file URL (or path to a file). If
this is an HTTP URL, Packer will download it and cache it between runs.

boot_command (array of strings) - This is an array of commands to type
when the virtual machine is first booted. The goal of these commands should
be to type just enough to initialize the operating system installer. Special
keys can be typed as well, and are covered in the section below on the
boot command. If this is not specified, it is assumed the installer will
start itself.

boot_wait (string) - The time to wait after booting the initial virtual
machine before typing the boot_command. The value of this should be
a duration. Examples are 5s and 1m30s which will cause Packer to wait
five seconds and one minute 30 seconds, respectively. If this isn't
specified, the default is 10s or 10 seconds.

disk_size (number) - The size, in megabytes, of the hard disk to create
for the VM. By default, this is 40000 (about 40 GB).

export_opts (array of strings) - Additional options to pass to the
VBoxManage
export. This
can be useful for passing product information to include in the resulting
appliance file. Packer JSON configuration file example:

A VirtualBox VM
description may
contain arbitrary strings; the GUI interprets HTML formatting. However, the
JSON format does not allow arbitrary newlines within a value. Add a
multi-line description by preparing the string in the shell before the
packer call like this (shell > continuation character snipped for easier
copy & paste):

floppy_dirs (array of strings) - A list of directories to place onto
the floppy disk recursively. This is similar to the floppy_files option
except that the directory structure is preserved. This is useful for when
your floppy disk includes drivers or if you just want to organize it's
contents as a hierarchy. Wildcard characters (*, ?, and []) are allowed.

floppy_files (array of strings) - A list of files to place onto a floppy
disk that is attached when the VM is booted. This is most useful for
unattended Windows installs, which look for an Autounattend.xml file on
removable media. By default, no floppy will be attached. All files listed in
this setting get placed into the root directory of the floppy and the floppy
is attached as the first floppy device. Currently, no support exists for
creating sub-directories on the floppy. Wildcard characters (*, ?,
and []) are allowed. Directory names are also allowed, which will add all
the files found in the directory to the floppy.

format (string) - Either ovf or ova, this specifies the output format
of the exported virtual machine. This defaults to ovf.

guest_additions_mode (string) - The method by which guest additions are
made available to the guest for installation. Valid options are upload,
attach, or disable. If the mode is attach the guest additions ISO will
be attached as a CD device to the virtual machine. If the mode is upload
the guest additions ISO will be uploaded to the path specified by
guest_additions_path. The default value is upload. If disable is used,
guest additions won't be downloaded, either.

guest_additions_path (string) - The path on the guest virtual machine
where the VirtualBox guest additions ISO will be uploaded. By default this
is VBoxGuestAdditions.iso which should upload into the login directory of
the user. This is a configuration
template where the Version
variable is replaced with the VirtualBox version.

guest_additions_sha256 (string) - The SHA256 checksum of the guest
additions ISO that will be uploaded to the guest VM. By default the
checksums will be downloaded from the VirtualBox website, so this only needs
to be set if you want to be explicit about the checksum.

guest_additions_url (string) - The URL to the guest additions ISO
to upload. This can also be a file URL if the ISO is at a local path. By
default, the VirtualBox builder will attempt to find the guest additions ISO
on the local file system. If it is not available locally, the builder will
download the proper guest additions ISO from the internet.

guest_os_type (string) - The guest OS type being installed. By default
this is other, but you can get dramatic performance improvements by
setting this to the proper value. To view all available values for this run
VBoxManage list ostypes. Setting the correct value hints to VirtualBox how
to optimize the virtual hardware to work best with that operating system.

hard_drive_interface (string) - The type of controller that the primary
hard drive is attached to, defaults to ide. When set to sata, the drive
is attached to an AHCI SATA controller. When set to scsi, the drive is
attached to an LsiLogic SCSI controller.

sata_port_count (number) - The number of ports available on any SATA
controller created, defaults to 1. VirtualBox supports up to 30 ports on a
maximum of 1 SATA controller. Increasing this value can be useful if you
want to attach additional drives.

hard_drive_nonrotational (boolean) - Forces some guests (i.e. Windows 7+)
to treat disks as SSDs and stops them from performing disk fragmentation.
Also set hard_drive_discard to true to enable TRIM support.

hard_drive_discard (boolean) - When this value is set to true, a VDI
image will be shrunk in response to the trim command from the guest OS.
The size of the cleared area must be at least 1MB. Also set
hard_drive_nonrotational to true to enable TRIM support.

headless (boolean) - Packer defaults to building VirtualBox virtual
machines by launching a GUI that shows the console of the machine
being built. When this value is set to true, the machine will start
without a console.

http_directory (string) - Path to a directory to serve using an
HTTP server. The files in this directory will be available over HTTP that
will be requestable from the virtual machine. This is useful for hosting
kickstart files and so on. By default this is an empty string, which means
no HTTP server will be started. The address and port of the HTTP server will
be available as variables in boot_command. This is covered in more detail
below.

http_port_min and http_port_max (number) - These are the minimum and
maximum port to use for the HTTP server started to serve the
http_directory. Because Packer often runs in parallel, Packer will choose
a randomly available port in this range to run the HTTP server. If you want
to force the HTTP server to be on one port, make this minimum and maximum
port the same. By default the values are 8000 and 9000, respectively.

iso_interface (string) - The type of controller that the ISO is attached
to, defaults to ide. When set to sata, the drive is attached to an AHCI
SATA controller.

iso_target_path (string) - The path where the iso should be saved
after download. By default will go in the packer cache, with a hash of the
original filename as its name.

iso_urls (array of strings) - Multiple URLs for the ISO to download.
Packer will try these in order. If anything goes wrong attempting to
download or while downloading a single URL, it will move on to the next. All
URLs must point to the same file (same checksum). By default this is empty
and iso_url is used. Only one of iso_url or iso_urls can be specified.

keep_registered (boolean) - Set this to true if you would like to keep
the VM registered with virtualbox. Defaults to false.

output_directory (string) - This is the path to the directory where the
resulting virtual machine will be created. This may be relative or absolute.
If relative, the path is relative to the working directory when packer
is executed. This directory must not exist or be empty prior to running
the builder. By default this is output-BUILDNAME where "BUILDNAME" is the
name of the build.

post_shutdown_delay (string) - The amount of time to wait after shutting
down the virtual machine. If you get the error
Error removing floppy controller, you might need to set this to 5m
or so. By default, the delay is 0s or disabled.

shutdown_command (string) - The command to use to gracefully shut down the
machine once all the provisioning is done. By default this is an empty
string, which tells Packer to just forcefully shut down the machine unless a
shutdown command takes place inside script so this may safely be omitted. If
one or more scripts require a reboot it is suggested to leave this blank
since reboots may fail and specify the final shutdown command in your
last script.

shutdown_timeout (string) - The amount of time to wait after executing the
shutdown_command for the virtual machine to actually shut down. If it
doesn't shut down in this time, it is an error. By default, the timeout is
5m or five minutes.

skip_export (boolean) - Defaults to false. When enabled, Packer will
not export the VM. Useful if the build output is not the resultant image,
but created inside the VM.

ssh_host_port_min and ssh_host_port_max (number) - The minimum and
maximum port to use for the SSH port on the host machine which is forwarded
to the SSH port on the guest machine. Because Packer often runs in parallel,
Packer will choose a randomly available port in this range to use as the
host port. By default this is 2222 to 4444.

ssh_skip_nat_mapping (boolean) - Defaults to false. When enabled, Packer
does not setup forwarded port mapping for SSH requests and uses ssh_port
on the host to communicate to the virtual machine.

vboxmanage (array of array of strings) - Custom VBoxManage commands to
execute in order to further customize the virtual machine being created. The
value of this is an array of commands to execute. The commands are executed
in the order defined in the template. For each command, the command is
defined itself as an array of strings, where each string represents a single
argument on the command-line to VBoxManage (but excluding
VBoxManage itself). Each arg is treated as a configuration
template, where the Name
variable is replaced with the VM name. More details on how to use
VBoxManage are below.

vboxmanage_post (array of array of strings) - Identical to vboxmanage,
except that it is run after the virtual machine is shutdown, and before the
virtual machine is exported.

virtualbox_version_file (string) - The path within the virtual machine to
upload a file that contains the VirtualBox version that was used to create
the machine. This information can be useful for provisioning. By default
this is .vbox_version, which will generally be upload it into the
home directory. Set to an empty string to skip uploading this file, which
can be useful when using the none communicator.

vm_name (string) - This is the name of the OVF file for the new virtual
machine, without the file extension. By default this is packer-BUILDNAME,
where "BUILDNAME" is the name of the build.

vrdp_bind_address (string / IP address) - The IP address that should be
binded to for VRDP. By default packer will use 127.0.0.1 for this. If you
wish to bind to all interfaces use 0.0.0.0.

vrdp_port_min and vrdp_port_max (number) - The minimum and maximum port
to use for VRDP access to the virtual machine. Packer uses a randomly chosen
port in this range that appears available. By default this is 5900 to
6000. The minimum and maximum ports are inclusive.

The boot_command configuration is very important: it specifies the keys to
type when the virtual machine is first booted in order to start the OS
installer. This command is typed after boot_wait, which gives the virtual
machine some time to actually load the ISO.

As documented above, the boot_command is an array of strings. The strings are
all typed in sequence. It is an array only to improve readability within the
template.

The boot command is sent to the VM through the VBoxManage utility in as few
invocations as possible.

There are a set of special keys available. If these are in your boot
command, they will be replaced by the proper key:

<wait> <wait5> <wait10> - Adds a 1, 5 or 10 second pause before
sending any additional keys. This is useful if you have to generally wait
for the UI to update before typing more.

<waitXX> - Add an arbitrary pause before sending any additional keys. The
format of XX is a sequence of positive decimal numbers, each with
optional fraction and a unit suffix, such as 300ms, 1.5h or 2h45m.
Valid time units are ns, us (or µs), ms, s, m, h. For example
<wait10m> or <wait1m20s>

Any printable keyboard character, and of these "special" expressions, with the
exception of the <wait> types, can also be toggled on or off. For example, to
simulate ctrl+c, use <leftCtrlOn>c<leftCtrlOff>. Be sure to release them,
otherwise they will be held down until the machine reboots.

To hold the c key down, you would use <cOn>. Likewise, <cOff> to release.

In addition to the special keys, each command to type is treated as a
template engine. The
available variables are:

HTTPIP and HTTPPort - The IP and port, respectively of an HTTP server
that is started serving the directory specified by the http_directory
configuration parameter. If http_directory isn't specified, these will be
blank!

Packer will automatically download the proper guest additions for the version of
VirtualBox that is running and upload those guest additions into the virtual
machine so that provisioners can easily install them.

Packer downloads the guest additions from the official VirtualBox website, and
verifies the file with the official checksums released by VirtualBox.

After the virtual machine is up and the operating system is installed, Packer
uploads the guest additions into the virtual machine. The path where they are
uploaded is controllable by guest_additions_path, and defaults to
"VBoxGuestAdditions.iso". Without an absolute path, it is uploaded to the home
directory of the SSH user.

In order to perform extra customization of the virtual machine, a template can
define extra calls to VBoxManage to perform.
VBoxManage is the command-line
interface to VirtualBox where you can completely control VirtualBox. It can be
used to do things such as set RAM, CPUs, etc.

Extra VBoxManage commands are defined in the template in the vboxmanage
section. An example is shown below that sets the memory and number of CPUs
within the virtual machine:

The value of vboxmanage is an array of commands to execute. These commands are
executed in the order defined. So in the above example, the memory will be set
followed by the CPUs.

Each command itself is an array of strings, where each string is an argument to
VBoxManage. Each argument is treated as a configuration
template. The only available
variable is Name which is replaced with the unique name of the VM, which is
required for many VBoxManage calls.